Meeting Abstract

25.3  Monday, Jan. 4  Thermotaxis of Jumping Beans WEST, DM*; HU, DL; Georgia Institute of Technology; Georgia Institute of Technology dwest6@gatech.edu

The Mexican Jumping Bean consists of a moth larva living inside a hollow seed. To avoid overheating by the sun, the bean rocks and rolls along thermal gradients. In this study we investigate the efficacy of the bean’s thermal sensing and rolling locomotion. We build a one dimensional bean track with a fixed heat source at one end. Using time-lapse photography, we record the bean’s path along the track and characterize its random walk by an average speed, u, and a diffusion coefficient, D (which is related to the standard deviation of the speed). We compare the speeds of the larva both with and without a shell, and find that the larva without a shell has a higher speed and a lower diffusion coefficient. Moreover, we use speed and diffusion to characterize the efficacy of the motion of the larva in different shell shapes.